I've just installed Ubuntu 9.10 on my desktop machine (laptop). I have /home in a separate partition, so my usual habit is to destroy the old OS and install afresh. Most applications manage to do the right thing when they see my $HOME, as long as I keep the same uid.
Of course, before you do this, it's great to preserve a list of the extras that you had installed … dpkg will list them, but it formats the output for a tty even when being piped, so you have to trick it with the COLUMNS envariable to get full package names …
$ COLUMNS=200 dpkg -l > ~/9.04.dpkg.list
Anyway, once the new OS is installed & running, grab the equivalent list and compare the two … we're interested in seeing any package that was in the 9.04 list that isn't in the 9.10 list …
$ COLUMNS=200 dpkg -l > ~/9.10.dpkg.list
$ for i in $(tail -n +6 9.04.dpkg.list | awk '{print $2}')
> do
> grep " $i " 9.10.dpkg.list >/dev/null || echo $i
> done > 9.10.notin
That was 1009 packages on my machine, so I has a quick look through by eye and identified the best ones … many were libraries, so they could all be ignored. I got it down to 75 entries pretty quick. I edited 9.10.notin and deleted every line with an un-necessary entry, and then …
$ sudo aptitude install $(cat 9.10.notin)
This makes sure that I don't forget about supertuxkart!